package utils;

import com.mysql.cj.jdbc.MysqlDataSource;

import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

/**
 * @author 李夏
 * @version 1.0
 */
public class DBUtil {
    private static volatile DataSource dataSource = null;
    private static DataSource getDataSource() {
        if(dataSource==null) {
            synchronized (DBUtil.class) {
                if(dataSource ==null){
                    dataSource = new MysqlDataSource();
                    ((MysqlDataSource)dataSource).setUrl("jdbc:mysql://127.0.0.1:3306/school?characterEncoding=utf8&useSSL=false&serverZoneTime=UTC");
                    ((MysqlDataSource)dataSource).setUser("root");
                    ((MysqlDataSource)dataSource).setPassword("1234qwer");
                }
            }
        }
        return dataSource;

    }

    public static Connection getConnection() throws SQLException {
        return getDataSource().getConnection();
    }

    public static void close(Connection connection, PreparedStatement preparedStatement, ResultSet resultSet) {
        if(resultSet != null) {
            try {
                resultSet.close();
            } catch (SQLException throwables) {
                throwables.printStackTrace();
            }
        }
        if(preparedStatement != null) {
            try {
                preparedStatement.close();
            } catch (SQLException throwables) {
                throwables.printStackTrace();
            }
        }
        if(connection != null) {
            try {
                connection.close();
            } catch (SQLException throwables) {
                throwables.printStackTrace();
            }
        }
    }

}
